We're not going to go into detail on the installation procedures here, both since a full walkthrough is beyond the scope of this article, and because doing so would be to encourage you to break the conditions of the OS X license, but you can find step by step instructions in the forums at tonymacx86.com.
Post-install
Kexts are essentially folders full of files, the most important of which is the plist, which contains the specific settings for a piece of hardware. If your installation isn't running well, hunt around in /Library/Extensions for a .kext file which applies to the kit in question, right-click it and select 'Show package contents'. Open up the plist file in a text editor, and edit away.
If this process doesn't work – and if you're fumbling around in the dark, it probably won't – then go online and hunt around the tonymacx86.com forums. It's very possible that a fellow Hackintosher has run into the same problem as you and will have at least a partial solution.
All done?
It's possible to upgrade an installed Hackintosh to the latest version of OS X but, again, we wouldn't put any money on it working well. If you've got a system up to the point where it's usable and relatively bug free, cut your losses.
Don't rely on a Hackintosh as your primary machine; these things tend to be fleeting at best, and may suddenly give up the ghost at any time. But once you've created one, you'll no doubt have a better understanding of the way the Mac and OS X works – perfect for when you pick up some official Apple hardware and do El Capitan the right way.